Elements of Life 3.1

Organic compounds have a carbon backbone

• 4 major categories of bio organic compounds.

  • lipids (fats oils wax)
  • carbohydrates (sugar, starch)
  • proteins (enzymes)
  • nucleic acids (DNA)

What are the characteristics of life?

1. made of a cell(s)

2. homeostasis

3. grow & develop

4. reproduce same species - DNA

5. react to stimuli

6. metabolism (+energy - waste)

7. adapt to environment

Energy 3.2

Potential vs Kinetic

Chemical and physical energy

Laws of Thermo Dynamics

Energy for Life 3.3

1. Chemosynthesis - uses inorganic chemicals to make energy.

Energy for cellular respiration. Who: bacteria - extremophiles.

Where: extreme conditions - acidic, no light, cold, pressure, hot

What: makes organic compounds from inorganic sources.

2. Photosynthesis - uses light energy to make - glucose and waste

product O2 (diagram page 61 figure 3.11)

• learn equation for both photosynthesis and respiration - BALANCED

From Species to Ecosystems 3.4

quark
electron
proton/neutron
nucleus
atom
element
molecule
compound
organelles
cell
tissue
organ
organ system
organism
species
population
community
ecosytem
biome
biosphere
Earth
solar system
universe

From Species to Ecosystem 3.4

Energy Transfer

• from abiotic to biotic through the process of chemosynthesis or photosynthesis
• begins with an energy source
• producer does the biotic transformation
• through primary productivity it makes biomass
• transfer of this energy through organisms is a food chain
• each step in a food chain is a trophic level.
• A food chain shows the direction and flow of energy

Quercus alba
Producer --> 1oConsumer --> 2oC --> 3oC -->
Autotroph Heterotroph Hetero Hetero
1st trophic Herbivore omnivore carnivore
2nd trophic 3rd trophic 4th trophi

Bioaccumulation

• The build up of a substance in the tissues of an organism
• The substance can not be ‘useful’, easily broken down, water soluble
• Therefore it is a long-lived, typically fat soluble substance

Biomagnification

• Is the exponential increase in a substance as you go up the food chain.
• In order to biomagnify you must first bioaccumulate it

Biogeochamical cycles

Nitrogen Cycle
Organisms need nitrogen for nucleic acids, amino acids, peptides, and proteins.

Atmospheric nitrogen N2 – is not bioavailable

Vocabulary

1. Nitrogen fixation

• Lightening fixation – inorganic – converts to bioavailable form NH3-
• biologic fixation – cyanobacteria, rhizobium bacteria (root nodules of legumes – beans, peas, clover)

1. Ammonification

• converting waste back to ammonia

1. Nitrification

• converting of NH3 to Nitrites and Nitrates (NO2 and NO3)
• fertilizer by bacteria in soil

1. Uptake and Assimilation

• converting nitrates into amino acids and proteins into tissue

1. Denitrification

• returning N2 to the atmosphere by bacteria deep in anoxic soil.

Phosphorous Cycle

• Unique – mineral cycle source and sink rocks
• Use/need: cellular level to transfer energy!
• Increase in dissolved phosphates causes increase in primary producers in aquatic environments. Major source of water pollution

Sulfur Cycle

• Unique – mineral cycle – source/sink rocks
• Use/need proteins, regulating global climate, acid precipitation
• We release it via burning of fossil fuels and upset climate and acid balance